one plastic drinking straw
1. Place your balloon on the top end of the drinking straw. Fasten a rubber band securely around the balloon so that it is sealed to the end of your straw.
2. Cut out two paper fins, using the fin guide. Slip first fin into the slot on second fin and tape them together. Now tape them to the bottom of your straw. Leave a little room at the bottom so you can put your lips around the straw.
3. While holding the rubber band against the balloon (so it doesn’t fly off), blow up your balloon.
4. Blastoff! Let your balloon-rocket fly! Try different sizes of fins and balloons. See how high you can make your rocket go.